Fleur and her husband, whose hand she held tightly as they hurried up the stairs from the Floo, were among the last to arrive. Why they appeared behind the others was their own business.
The fighting was well underway by the time they made it up to Level Two, with forces from both sides furiously casting spells in every direction. Bill's hand was torn from Fleur's grasp as he charged into combat. Fleur was left for a moment, staring after him, all too aware that he had run off without much of a goodbye.
She ran the other direction, casting shields and stunning spells as she went until she came across the first fallen body. This one was a Death Eater she didn't recognize, and after a quick check, he proved to be quite dead. She moved on to find one of the Order unconscious, and she knelt beside him to try and bring him around.
As the battle died down around her, she continued on, checking on the status of friend and foe alike.